Credit cards worth it?

I'm thinking of getting a credit card -is it worth it? I'm 22, in the UK and thinking about getting a credit card -I don't feel I need one (not a big or enthusiastic spender) apart from establishing a credit rating -is it worth it? I understand the benefits -insurance, cash-back etc but it seems like a hassle -I'm perfectly happy just spending money that I have using my debit card. However, as credit scores are partly based on duration of credit history I'm thinking I should get a credit card if only to prove to future mortgage providers (perhaps 3 or so years in the future) that I'm responsible with credit etc. As I've also learnt that cancelling cards reflects badly on credit rating so any card I do take out is hopefully going to last me a long time. I bank with Natwest and am thinking of taking out a credit card with them as it would be easy to pay it off each month with my current online banking setup. But there are no benefits/cash back with it. Aren't credit cards desperate for people to sign up? I might not too excited about credit cards but I don't want to miss out on decent benefits like cash-back etc if there's available. In summary is it worth getting a credit card and if yes, which is the easiest to use, best 'perks' and recommended over the long term so I don't end up dealing with the 'financial clutter' resulting in opening up other cards in the future? Any UK specific advice/opinion would be much appreciated! Thanks